-LRB- CNN -RRB- -- North Korea has confirmed to Swedish diplomats that it is holding an American citizen , the U.S. State Department said Friday .

The State Department has declined to confirm the identity of the citizen , citing privacy issues . But the family of 85-year-old Merrill Newman of Palo Alto , California , has said he has been detained in North Korea since October 26 .

Washington does not have diplomatic relations with Pyongyang , and it has been working through Sweden -- the U.S. protecting power in North Korea -- to obtain information about the American .

`` We are working in close coordination with representatives of the Embassy of Sweden to resolve this issue , and they also have requested on a daily basis consular access , '' State Department spokeswoman Jennifer Psaki told reporters .

The revelation came the same day that Newman 's wife , Lee , pleaded for his release .

`` The family feels there has been some dreadful misunderstanding leading to his detention and asks that -LRB- North Korea -RRB- work to settle this issue quickly and to return this 85-year-old grandfather to his anxious , concerned family , '' she said in a statement .

Newman , a Korean War veteran and retired financial consultant , was last seen aboard a flight from Pyongyang to Beijing . Just minutes before the plane was to depart , he was removed from the flight by North Korean authorities , the family has said .

`` He has been detained somewhere in North Korea since that time , '' Newman 's wife said in the statement .

According to the family , Newman and a traveling companion , Bill Hamrdla , had been on a 10-day organized private tour of North Korea .

The family has said Newman suffers from a heart condition and only had enough medication for the trip .

`` We have had no word on the state of his health , whether or not the medications sent to him through the Swedish Embassy in North Korea have been delivered or why he was detained , '' the statement said .

The day before Newman was to leave North Korea , he and his tour guide met with `` one or two Korean authorities , '' his son said .

During that meeting , Newman 's service record was discussed , Jeff Newman said .

`` I understand my dad was a bit bothered , '' Newman told CNN . But neither he nor his traveling companion believed there was an issue .

The United States this week issued a warning to American citizens against all travel to North Korea , which has become a magnet for adventure travelers after Pyongyang lifted some of its travel restrictions .

Newman was a customer of Juche Travel Services of London , company spokesman David Thompson said in a written statement .

`` The tour arrangements were handled by the Korea International Travel Company , '' Thompson said . `` Mr. Newman had in place all necessary and valid travel documents to take his tour . We have no information concerning what has occurred to result in the current situation . ''

The 10-day private tour , which included the use of a tour guide , was the culmination of months of planning , Newman 's wife said .

`` The postcards sent to friends while on that trip describe good times , good weather and knowledgeable guides , '' she said in the statement .

The family 's statement came a day after U.S. Secretary of State John Kerry called on North Korea to release Americans being held , calling the detentions `` very , very disturbing choices by the North Koreans . ''

Newman is one of two American citizens being held in North Korea .

The other one , Kenneth Bae , was arrested in November 2012 and sentenced in May to 15 years of hard labor . The North Korean government has said he was found guilty of `` hostile acts '' and attempts to topple the government .

North Korea has not publicly said why it is holding Newman .

Is American man detained in North Korea a bargaining chip ?

Among the possibilities is his military service . He served as an Army infantry officer during the Korean War , which saw North Korea fight South Korea , the United States and the United Nations between 1950 and 1953 .

An armistice signed in 1953 ended the three-year war between North Korea and South Korea . The two sides technically remain at war .

It is also possible North Korean authorities mistook him for another Merrill Newman , a Korean War veteran awarded the Silver Star for valor in combat .

North Korean authorities are known to routinely run background checks on foreigners , travel agencies warn potential visitors .

The first the decorated combat veteran heard about Newman 's detention was in a telephone call from the San Jose Mercury News , which first reported the news of the American 's detention .

`` I thought it was a coincidence . I did n't think much about it , '' Merrill Newman of Beaverton , Oregon , told CNN .

Of his service during the war , he only said : `` I went there , did what I was told and went home , went to college and started a family . ... That 's what you did in those days . ''

How you travel to North Korea

News of the apparent detention came as talks were under way between the United States and China , North Korea 's closest ally , about reviving negotiations to dismantle Pyongyang 's nuclear program .

The timing raises questions about whether North Korea plans to use Newman as a bargaining chip in the negotiations , a move the West has previously accused it of doing to try to gain concessions with negotiations .

Newman 's detentions bring to at least seven the number of American citizens who have been detained by North Korea , including four who allegedly entered the country illegally , according to the State Department .

Two other U.S. citizens who entered the country on valid visas were arrested for other reasons , and U.S. officials have received reports of other Americans being arbitrarily detained , according to the State Department .

Previous Americans detained in North Korea have been released when high-profile visitors have traveled to the country to plead their case . Most notably , former Presidents Bill Clinton and Jimmy Carter went on two separate occasions in 2010 .

Former New Mexico Gov. Bill Richardson , a former ambassador to the United Nations , has visited North Korea a number of times over the years , most recently this year to discuss the release of Bae .

Richardson 's spokeswoman , Caitlin Kelleher , said he has been `` in touch with his North Korean contacts '' regarding Newman 's detention .

The photos North Korea does n't want you to see

CNN 's Augie Martin , Christopher Laible , Sarah Baker and Elise Labott contributed to this report .

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Detained man 's wife : `` The family feels there has been dreadful misunderstanding ''

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`` The postcards sent to friends ... describe good times , good weather , '' she said

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State Department has declined to identify the American , citing privacy issues

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But family of Merrill Newman , 85 , says he 's been held by North Korea since October